Slapping some solar panels on a McMansion to offset the energy use of a walk-in humidor and calling it “green” is something of a canard. To be truly “green” or “sustainable” or “environmentally friendly,” or any number of loosely defined terms, a home needs to be thought-through and accordingly designed from slab to stud to ceiling fan. It should be well insulated and generate as much power as it uses, just for starters. It also has to be only minimally polluting to the ground water, and use sustainably harvested and renewable materials in construction. And lastly, it should have that difficult-to-define but visually obvious quality of not being a total “Look at me!” eyesore.
Meeting all of these criteria is relatively easy if you’re building a five-hundred-square-foot shack. But many Vineyard home-owners are looking for something else: a dream home. Dream homes are beautiful. Dream homes are spacious. Dream homes have great views, and boast meticulous craftsmanship and lush grounds. The Davis house in Chilmark is a dream home, even if the Davises don’t use that term.
Karen and Dave Davis, partnering with West Tisbury’s South Mountain Company, have built a comfortable and visually delightful 3,300-square-foot house perched on a hill overlooking Chilmark Pond and the ocean beyond. The main floor features a round kitchen flowing into a spacious living area with a large, stone fireplace, many windows, and tremendous views. A roomy screened-in porch is outside the kitchen, and a large deck runs the length of the house, with the master suite on the other end. The lower level downstairs includes three additional bedrooms and a workshop. But, in addition to beauty and comfort to rival any Vineyard home, the house is likely “greener” than any on the Island.
This did not happen by accident. Karen and Dave made a conscious decision to build a house that reflects their values as well as their sense of style. Karen is an organic farmer in central Massachusetts, where she owns Sweet Water Farm in Peters-ham, and Dave is a retired family doctor. A visitor to their Chilmark home is likely to be continually impressed with how much thought they and South Mountain have put into their Vineyard year-round getaway.
The couple found like values in South Mountain Company, a design and build firm that has been doing innovative and environmentally conscious work on-Island since 1975. The Davises actually started out the design process with another builder, but the “house was not turning out the way we wanted,” says Dave. South Mountain, veterans of green building techniques, understood their need for a beautiful home in harmony with the environment.
“I’ve come to the Vineyard every summer of my life,” says Karen, “and seeing how fragile the environment is, here even more than elsewhere” was the prime motivation behind their efforts. Ryan Bushey, the lead designer of the home, recalls being struck by the Davises’ “almost-spiritual connection to the environment and the Island.”
Ryan states simply that there is no inherent trade-off between comfort and environmental values. “The thing that resonates with people unfamiliar with green building techniques is that the home is going to be more comfortable, less drafty, use less energy.” South Mountain President John Abrams goes further: Noting the “spectacular” growth in the last few years in green building techniques, he says, “This is not something exotic. This is how we’re all going to live.”
Design began in July of 2005, and construction ran from May 2006 to May 2008, or “just short of forever” to Dave, but he acknowledges that it “takes time to make the good choices.” Dave involved himself heavily in the project, right down to assisting the cabinetmaker on the hand-built, curved kitchen cabinets. He says there was an “experimental quality” to figuring out the design, companies, and materials to use, though he stresses that South Mountain did the research for those decisions. Ryan describes Dave as “hands-on,” and says of the continuous interaction with the Davises: “Dave and Karen were the reason this house was so successful.”
The respect is mutual: “We really enjoyed the process of building the house. Ryan is an incredibly good listener,” says Dave.
At the Davises’ request, the overall design eschews straight lines for subtle curves in many of the walls, woodwork, and roof lines. “The curves added another layer of complexity to the construction,” Ryan says. And while the rustic and serpentine touches add to the overall natural feel of the home, they’re not essential to the green systems that lessen the house’s environmental impact. A more traditional-looking home can easily be as energy-efficient.
What makes the Davises’ house so green? First, it’s a net generator of energy – meaning that unlike the vast majority of buildings, the Davis house creates more energy on the whole than it uses. A photovoltaic (PV) solar array on the roof of the garage generates 6 kilowatts of energy on bright, sunny days. Inside the house, a readout shows the amount of electricity being generated and the amount being used; on a recent visit, when the system was generating at maximum capacity, usage was a mere 0.49 kilowatt, primarily for the refrigerator. Even on overcast days the system creates electricity, but on dark days and at night the house draws electricity from the grid. NSTAR pays the Davises for the electricity they generate in excess of what they use.
A solar system also heats their hot water, with panels on the roof of the home where propylene glycol (a biodegradable anti-freeze) is heated by the sun and then piped to a basement unit where the heat is transferred to insulated tanks of water. The system is so efficient, even in cloudy weather, that the electric back-up system has never been used, even with up to nine people in the house. In fact when not used, the system often collects too much heat and has to shut down. Fortuitously, the floor of the lower level was plumbed for radiant heating, and beginning this winter the excess heat generated by the hot water system will heat that area of the home.
Not that the Davis house needs much heating. The house is built with an extremely tight building envelope that minimizes heating and cooling needs. South Mountain constructed walls with ten inches between the inner and outer walls. The outer two inches were covered with closed-cell, high-density, spray-foam insulation, and the rest of the cavity was filled with blown-in cellulose – essentially recycled newspapers with a borax flame-retardant. The R-values, measures of insulating effectiveness, are well above minimum code requirements. For example, the ceilings have a 47 R-value (38 is code), the walls have a 44 R-value (19 is code), and the house is so tight that even the concrete slab it is built on is insulated with a 32 R-value (10 is code). Low-emissive, energy-efficient, triple-glazed windows help prevent heat loss or gain too.
The design also incorporates passive-solar techniques, meaning that the winter sun shines through the many windows and onto the terra cotta floor, warming it and the whole house. The fact that the site offers both beautiful views to the south and terrific southern exposure substantially eased the incorporation of passive solar. In summer, the angle of the warming sun is higher and the rays are mostly blocked by the eaves, keeping the house cool. Since the insulation in the building envelope prevents heat from getting in, and the many windows catch the cooling ocean breezes for cross-ventilation, air conditioning is not needed.
At night or on overcast days during the colder months, two pellet stoves supplement the heating. Pellet stoves use pellets of compressed sawdust, a renewable resource (typically waste from furniture or cabinetmaking), that burn extremely clean with a tiny fraction of the emissions and maintenance of a wood stove.
The one-inch-thick floor tiles are set on three sheets of gypsum and a layer of concrete backerboard to provide the necessary thermal mass, that is, a mass that will warm up during the day and release the heat in the evening and overnight. The floor tiles, crafted in Mexico, feel fantastic under bare feet and have varied warm tones, and a few even have dog prints from some careless south-of-the-border canine. The Davises – whose black Lab, Kelly, patrols the floor – chose to incorporate the unusual tiles.
The floor also has sections of translucent glass tile that cast light into the lower level, lessening lighting needs. At night, any lights on in the lower level, Dave says, “cast a beautiful orange glow” up into the main living area. With the large number of windows and a clerestory (a narrow wall of windows above the roof line) that brings light deep into the house, need for artificial light is lessened. All electric lighting in the home uses either efficient compact-fluorescent bulbs (which use about a quarter of the electricity of standard incandescent bulbs) or hyper-efficient LEDs (light-emitting diodes, which use about an eighth).
John Abrams notes that for a part-time residence, the design of the Davis house has another major advantage: no need to “winterize” the residence. “This house is designed so you can come and go all year long; just shut the door and go.”
Another eco-friendly aspect of the house is the green roof, as in literally green – a roof covered with living plant material. The green roof covers the porch and kitchen, and is an excellent insulator, in addition to protecting the roof membrane and capturing storm water.
Perhaps the most rustic “green” aspect of the house is the incorporation of Clivus Multrum composting toilets, which use no water, and are different in look and feel than a typical toilet. In fact, while beautifully built into hand-crafted cabinetry, they still have the feel of an outhouse, though there is no odor due to electric fans in the system. Since the Davis house is so close to Chilmark Pond, they made the decision to use the composting toilets to help eliminate the excess nitrogen damaging our coastal ponds (see Composting toilets versus septic, below). The composting toilets can take a little getting used to, and Karen mentions that their daughter “hates them.” John Abrams says that while South Mountain has had a lot of successful projects using Clivus toilets, “I never thought I’d be putting them in million-dollar houses” – something he says he’s done several times now.
The house also has a gray-water system that catches water from the upstairs sinks and laundry in a cistern for use in watering the plants around the house. No fertilizers are used in keeping up the grounds, which feature beautiful gardens of only native plants, maintained by Indigo Farm, an Edgartown landscaping firm. The grounds also boast a distinctive nautilus-shaped outdoor shower (using solar hot water), which provides privacy as well as a wonderful water view from inside. And speaking of water views, the Davises are proud that the house is “almost invisible” from the beach and the pond.
Much of the material used in the house, particularly lumber, was salvaged. South Mountain has kept a detailed history of the materials that shows the unique lineage of almost every log, from cypress salvaged from the bottoms of Southern swamps to redwood cribbed from obsolete Falstaff brewery tanks in Nebraska to pine sheathing from Katharine Graham’s old house in West Tisbury. The garage, which was constructed primarily from materials salvaged from the small home that was on the site when the Davises bought the property, is in itself “visually delightful” to Dave. The entire house has natural touches, like handrails and newel posts made of logs, including a 600-pound piece of driftwood that was dragged off a north shore beach at considerable effort.
As for living in the house, Karen and Dave rave about the experience, though both admit that there has been some trial and error – any homeowner undertaking such a huge operation has likely felt the same way. The house is so tight, for example, that the fireplace doesn’t draw unless a window is open, which makes a fire on a cold winter night somewhat unattractive. Asked about flaws in the house, Dave says, “It sometimes feels too big.” They also say that the PV, solar hot water, Clivus, and gray-water systems in the house require a certain amount of attention. “You have to know what’s happening, and you need to watch it,” says Dave. Karen notes, “Dave has an interest in it, and does more than the average person might.”
Ryan agrees that Dave’s interest in the house gave South Mountain “a little bit more leeway in making [the house] more manipulatable than we might have with another homeowner,” but says that the maintenance issues in the house are no more than in a conventional home, just different. “The design of the house was intended to get rid of typical maintenance issues, like exterior painting for example.” But for the maintenance issues that do crop up, South Mountain provided an owners’ manual to the Davises, three volumes that include pictures of the house during construction, diagrams and blueprints, and literature on all the house’s systems.
Hopefully someday soon the features that make the Davis house unique will be ubiquitous in the home-building industry, and Ryan notes that the architects and builders he knows are almost all trying to include more green building techniques. And far from being simply high-end novelties, the design techniques transfer to more affordable projects: South Mountain is currently working on one in West Tisbury for the Island Housing Trust. But for now, Karen and Dave Davis are in the vanguard, and not worried about anyone’s perceptions; “We’re pretty weird to start,” says Karen.
While most houses require the cooperation of multiple contractors, the cast for the Davis house was DeMille-ian. South Mountain Company alone used eight designer/manager/engineer types, and eleven of its carpenters/shop crew. Here are some of the main subcontractors and suppliers, most of which are on-Island:
Matt Viaggio Insulation
Steve Gallagher Electric
Stonewall Management Plumbing
WH Russell Painting and flooring
Martha’s Vineyard Tile Company Tile
Robert Wilcoxson Ceramic Tile Tile installation
Circle Redmont (Melbourne, Florida) Glass block floor
Howard Hastings (Barre) and Dave Davis Kitchen cabinets
South Mountain Company Photovoltaic energy and solar hot water systems
Vineyard Alternative Heating Pellet stoves
Green Living Technologies (Rochester, New York) Green roof
Clivus New England Composting toilets and gray-water system
Indigo Farm Landscaping
